C90 advice
Author
Discussion

benjobanjo

Original Poster:

73 posts

107 months

Friday 16th February 2018
quotequote all
I've just bought a 1989 Honda C90 from a friend - it hasn't been used since early 2014.

It wouldn't start, so my mate got a new battery and spark plug for it - and it ran first time with no issues. I've just got the van and brought it home, the seller put some new petrol and oil in for me - and now it won't run. It sounds like it's trying, but dies out soon after.

My thoughts are maybe some old petrol was in the tank and has been disturbed in transit/when new petrol was added. I'm obviously a complete amateur with regards to bike maintenance, having only ever bought new before.... do you have any suggestions?

crofty1984

17,064 posts

235 months

Friday 16th February 2018
quotequote all
Clean out the carb. Ultrasonic bath is ideal but if not available, aerosol carb cleaner, an air line and poking a guitar string/wire brush wire down the jets will help.

SteelerSE

2,028 posts

187 months

Friday 16th February 2018
quotequote all
Check the choke. the cable may be knackered or it might just have been left on.
Empty the fuel completely and put new stuff in.
Sometimes when this sort of thing happens with my petrol mower I put Super Unleaded fuel in and that sorts it.

I'd try the easy stuff before taking the carb off.

WinstonWolf

72,863 posts

270 months

Friday 16th February 2018
quotequote all
I'd try it with the tank cap off too, just to make sure it's not a breather problem. Been there, done that...

Rubin215

4,201 posts

187 months

Friday 16th February 2018
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It's knackered.

I'll give you £10 for it...

whistle

OverSteery

3,794 posts

262 months

Friday 16th February 2018
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Check it still has a spark - only takes a minute and something could have come loose.

WinstonWolf

72,863 posts

270 months

Friday 16th February 2018
quotequote all
OverSteery said:
Check it still has a spark - only takes a minute and something could have come loose.
I did that with my C50 when I was about 14. It was a sunny day and I couldn't see the spark very clearly. I had always tested my Lego batteries by sticking my tongue on them so I naturally thought I would be fine putting my finger in the plug cap and kicking it over.

Don't put your finger in the plug cap and kick it over... yikes

joema

2,755 posts

210 months

Friday 16th February 2018
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Ha. I've had a few nasty surprises trying to kick over bikes to check for spark

Check the colour of the plug also.

Whip off the fuel hose and check fuel is getting through. Could have a blocked fuel filter.

Make sure choke works, i.e. on when cold then off when warm.

My old Honda had a similar issue with cutting out and it was a knackered distributer/coil.

Lazermilk

3,523 posts

112 months

Monday 19th February 2018
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No experience with C90s apart from a mates one when younger, but someone on here posted a link to this youtube channel which is pretty funny, some of things he has done with his little C90 is mad!

https://www.youtube.com/channel/UCVqpNG1R72i21jh-n...